In a fuel cell assembly of the kind wherein a current collector, a heat resisting insulator and an end plate are in turn arranged on each end of a fuel cell stack, the current collector is connected to a terminal brought out through the end plates.
Such a current collector construction is sufficient for a fuel cell assembly with an electrode area of 1000 cm.sup.2 or less. However, if such a construction is applied to a fuel cell assembly with an electrode area of 2000 to 3000 cm.sup.2, the current collecting efficiency becomes lowered, and deviation of output power occurs. It is therefore required to increase the number of terminals from one to two, three, four, five and so on with increase in the electrode area, for example, as shown in FIG. 8. A current collecting equipment of FIG. 8 has five terminals 7, which are connected to a current collector 4 and brought out through an insulator 5 and an end plate 6.
When the current collector 4 expands with heat during operation of the fuel cell assembly, the terminals 7 prevent the current collector 4 from free expansion, resulting in undulating deformation of the collector. This causes failure in electrical contact between the current collector and the electrode, resulting in a lowering of the current collecting efficiency and thus deterioration of the fuel cell characteristics.